How to think about Trinity and Incarnation
Jesus is an Eternal Member the Blessed Trinity
The Nicene Creed teaches us that God the Son is "God from God, Light from Light, true God from true God, begotten, not made, one in being with the Father." The Nicene Creed is not as clear about the fact that the Spirit is also one in being with the Father and Son, but this is what we mean when we use the word "Trinity" (Tri = Three + Unity, three Persons in One Being).
In entering our world and taking on our own human nature, God the Son never left the Godhead. He could not and did not break His eternal unity with the Father and Spirit; it is a unity of being, "from before all time." As Jesus revealed in the Gospel of John, "the Father and I are one."
The "descent" of God the Son from Heaven to Earth is not a spatial movement but a metaphysical movement.
- In His divine nature, the Son is outside of time and space; in His human nature, he, like us, is subject to the constraints of space and time.
- In His divine nature, the Son cannot suffer and die; in His human nature, like us, the Son did suffer and die.
- In His divine nature, the Son possessed a Divine Will which is necessarily in perfect conformity with the Father's Will; in His human nature, the Son had a mind and will like ours, though unbroken and unhindered by sin, which He offered to the Father in a truly human fashion (see, for example, the Agony in the Garden).
The Omnipresence of Father, Son, and Spirit
The Holy Trinity is the cause of all that is. All things are created "ex nihilo" (Latin, "out of nothing"). There is no eternal substance--or eternal space-time framework for matter and energy--apart from God's creation. He alone brings all things into being and sustains them in being.
Therefore, God is present as Creator in all that exists and in all who live: angels, saints, demons, the souls of the damned, our own souls on earth, every other living being, and the whole of the material world. If God were not sustaining us all in being right now, then we would cease to exist.
This means that the Father, Son, and Spirit are present to every spirit or soul in Hell. There is nowhere that the damned can go to depart from God. There is no "space" in the spiritual world. The very same thing that causes the joy of the good angels and the saints in Heaven--the presence of God--causes the torments of the evil spirits and souls of the damned in Hell.
So, in a very peculiar sense, God is "in" Hell, though not in the state of alienation from God that makes Hell hellish to those who have chosen not to serve God. They are in a state of being of their own making that makes them eternally unhappy.
God the Son is necessarily present to His own human soul in the "time" (such as it is) between His death on the Cross and His resurrection from the tomb. The hypostatic union ("personal union") between His divine nature and His human nature never ceased. In Jesus there is only one who, one hypostasis, one Person--the Eternal and Only-Begotten Son of God. That single Person possess two natures, the nature of God and the nature of a human being. After the Incarnation, that single, eternal, Divine Person is always united to His human nature.
In 451 AD, the Council of Chalcedon taught that the two natures of God the Son are not changed or confused (mixed together) by the personal union between them, but the union by means of being possessed by the same eternal person means that they cannot be separated, either. This doctrine of the Hypostatic Union developed against that of the Monophysites, who taught that the Incarnation brought about a single (mono) nature (physis) that was a blend of God-and-man, so that afterward, Jesus was not true God or true man, but a brand new, half-and-half mixture, with some traits of each. The council taught that:
- The two natures are not confused by being united.
- The powers of one nature are not shared automatically with the other. In His divine nature, Jesus acts with a divine consciousness and will. In His human nature, He acts with the power to suffer and die.
- The two natures remain unchanged by the union.
- By taking on a human nature, Jesus did not change His divine nature nor did He change human nature. After the Incarnation, He is true God and true man, not half-and-half or some other new kind of being (the heresy of monophysitism).
- The two natures are inseparably and indivisibly united by the Divine Person.
- The two natures are united by being the natures of a single Person. This is the "hypostatic union." "Hypo-stasis" is literally translated as "substance" or "subsistence" in Latin, but, in the theological context, the best English translation of "hypostatic union" is "personal union."